Blade sharpener



May 1950 R. R. SPENCER 2,507,826

BLADE SHARPENER Filed Sept. 12, 1947 2 Sheets-Sheet 1 INVENTOR PO VHLD 1Q. SPENCER 4 BY v /Zfi Z M ATTORNEY y 1950 R. R. SPENCER 2,507,826

BLADE SHARPENER Filed Sept. 12, 1947 2 Sheets-Sheet 2 INVENTOR. EON/41D SPENCER A TTOE'NEY Patented May 16, 1950 BLADE SHARPENER.

Ronald R. Spencer, Bloomfield, N. J., assignor to Spencer and Hell, Inc., Bloomfield, N. J a corporation of New Jersey Application September 12, 1947, Serial No. 773,597

1 Claim.

This invention relates to sharpening devices and is concerned more particularly with a blade sharpener.

Originally cutting edges were produced by an irregular grinding thereof between angularly held fiat surfaces of a pair of grinding stones. Ever since then attempts have been made to improve such antique method and a great many devices for grinding and sharpening blades have been proposed.

Devices for the sharpening of blades, e. g. blades of knives, as thus developed heretofore generally involved the utilization of rotatable grinding wheels or disks. Such devices, however, are not satisfactory in operation, since the grinding Surface tends to grind away uneven portions of the blade cutting edge, with the result that in the hands of the non-expert, i. e. in the hands of the general public, such devices cause an uneven sharpening, of the cutting edge and even a chipping of such edge. Proposals have also been made to construct sharpening devices involving the use of juxtaposed balls of steel, but such devices, likewise, have not solved the problem since in operation they were not efiicient as sharpening devices.

It is, therefore, one object of this invention to provide a device for the sharpening of b1ades--e. g. knife blades, razor blades, and so forth-which shallbe simple in construction and which shall be highly efficient as a sharpener. It is another object of this invention to provide such device which shall be simple in construction and which shall be highly efficient as a sharpener. It is another object of this-invention to provide such device which shall be adapted to sharpen the cutting edge evenly along its entire length. It is a further object of this invention to produce a device as described which shall not chip the cutting edge of the blade. Other objects and advantages of the device of my invention will appear from the description thereof hereinafter following.

The blade sharpener of my invention is illustrated in the drawings, forming part hereof, in

which:

Fig. 1 represents an elevational view in perspective, with one cover removed,

Fig. 2 represents a top view with covers removed,

Fig. 3 represents an elevational side view of a part of the device,

Fig. 4 represents a top view of a modification of the device of Figs. 1-3, with the top covers removed, and

Fig. 5 represents a sectional view on the line 5-5 of Fig. 4.

Referring to Fig. l, I have a housing comprising standing base i, a bottom part 2 and a top cover 3, which may be constructed of two sections, one section covering, half of the device being sbp p n F hebo m. part 2 and the top cover 3 may be two separate parts which. are inter-connected by way of a hinge or which may be glued or cemented together or otherwise joined to form an integral part. In the drawing only part of one section of the top-cover 3 is shown, the remainder being broken away to show the internal mechanism of the device. The base 2 may be provided with screw holes 9 where fixed fastening of the device to a support is desired.

The sharpening mechanism of the device comprises a plurality of pairs of juxtaposed balls or spherically shaped elements I" and I and 2' and 2", the balls or spheres of each pair being held in frictional point contact along the apex of the peripheries thereof. As illustrated in Fig. 3 the blade 3 tobe sharpened is broughtinto contact with the pairs of balls along the wall of its cutting edge and drawn. lengthwise between and in contact with such pairs of balls. Referring back to Fig. 1, the device contains of course a passageway for the insertion of the blade into the mechanism and for this reason the top cover 3 is provided with a transverse opening across the entire top and the bottom part 2 likewise contains on either side a slot or other opening, as indicated at 4, to permit the blade to be inserted and drawn through between the pairs of balls. The pairs of sharpening elements are aligned relative to each other so that the means to be sharpened are brought in contact with the spherically shaped sharpening means of each pair at or near thecontact of the spheres in a straight line defined by the cutting edge. The balls I' and. l" on the one handand the balls 2 and 2." on the other hand are held in firm frictional contact. The method of accomplishing such firm frictional contact of the complementary balls of each pair, as illustrated in the embodiment of the drawings, involves the provision of socket plates '5 and 5 with sockets 6 and 6 for the balls I and I, and-sockets l. and l for the balls 2 and 2". Theplatesfi and 5 are backed up by strong tension springs Band 8. Of course, it willjbe. appreciatedthat the frictional contact of the balls l and I andballs2 and 2" may be accomplished by. other means, e. g. separate arrangement for each pair, or otherwise, although naturally a sing-lespring tension unit, as illustrated, comprises a preferred manner of achievingthe. objective of frictional contact of the balls of each pair. As will appear from the description of the. operation of the device it should also be noted that one pair, to wit, in accordance with the description, pair I and I may be in firm frictionalcontact of a fixed type, i. e. without spring tension, so that this pair may be in fixed contactand does not necessarilyrequire a tension, contact. The housing may of course be constructed-of any desired material, metal. or plastic or other construction material. Also, it will: beeobviousathatthe. housingv may have any des red hap In; the drawingofrig: 1 Ihave merely illustrated what might be called a table model, which for purposes of design has an oval shape with a fiat base. Other models, such as wall models or simple devices to be held by the operators hand may of course be constructed.

In the device of my invention the balls of one pair, e. g. balls I and I are provided with a smooth surface. Such balls may be made for instance of steel or glass or any other material having a hard but smooth surface. A polished surface is desirable but not necessarily required. The balls of the other pair, 1. e. balls 2' and 2", are provided with an abrasive surface, e. g. a surface of carborundum or the like abrasive material. Such abrasive surface may be integral with the material of such balls or may be a peripheral element, as desired.

The balls I and on the one hand and the balls 2 and 2 on the other hand are in such frictional contact that the lengthwise passage of the blade does not, by itself, cause the balls to rotate. The balls may, however, be rotated by force, the purpose in such case being, however, merely to present to the blade surface from time to time a new ball surface. t is for this reason that the abrasive balls, i. e. in the drawings balls 2' and 2", must be held in contact by spring tension, whereas the smooth balls, 1. e. balls I and l, where the availability of a new ball surface is less important, may be held in fixed frictional contact. The

rotatable balls are, therefore, seated or nested in sockets having a complementarily concave and spherically shaped configuration, although other types of holding and encompassing means may be used in place of such sockets.

The most efiicient operation of the device is obtained where the balls or spheres do not rotate during the sharpening process and are during such process in continuous point contact at the apexes of the contacting spheres, although it is possible to operate the device in such manner that the balls, or some of them, are permitted to rotate slightly or to be forced apart very little during the sharpening process.

In the operation of the device of my invention the blade to be sharpened is repeatedly drawn through between both pairs of balls, either to and fro but preferably only in the direction from the abrasive balls to the smooth balls. The abrasive balls are designed to efficiently sharpen the cutting edge by efficient grinding along the wall of the cutting edge, without however affecting the sharp cutting edge itself and thus avoiding any accidental dulling thereof, whereas the smooth balls are adapted to smooth out and burnish any roughening caused by the abrasive balls. The pairs of balls thus cooperate to grind the blade along the walls of the cutting edge and at the same time to smooth out any resultant irregularities, to produce an extremely sharp smooth cuttin edge. Any metal forced out of alignment by the grinding balls is thus caused to flow back into alignment by the smooth burnishing balls.

It might be noted at this point that the device of my invention may of course comprise any plurality of pairs of contacting balls. I may thus provide, for instance, a triple arrangement, wherein one pair of abrasive balls is flanked on each side by a pair of smooth balls. Such device is, for instance, desirable where constant to and fro movement of the blade is a prime requisite of the sharpener.

It will also be understood that the sharpening elements I and I and 2' and 2". or at least the 4 smooth burnishing elements I and I", do not necessarily have to be constructed in the shape of balls, so long as the surfaces thereof adapted to be in contact with the walls of the cutt edge of the blade have a spherical or otherwise rounded curved configuration, each pair of elements constituting a. stationary bearing of spherically shaped contacting parts adapted to sharpen the tapered walls of the cutting edge of a blade.

The device of the invention combines, therefore, efficient grinding operation with a burnishing effect, so that the final result is the production of a finely ground sharp and yet straight cutting edge with smooth walls. The sharpener of the invention may be used for domestic purposes, 6. g. the sharpening of kitchen knives, razor blades. scissors and so forth, or for industrial purposes, e. g. the sharpening of cutting tools. In either case it makes it possible for an inexperienced operator to efficiently sharpen a blade, an achievement not possible to the same degree with devices as heretofore known.

Figs. 4 and 5 illustrate an embodiment wherein I have a plurality of four pairs of sharpening balls instead of a plurality of two pairs of sharpening balls as in Figs. 1 and 2.

In the embodiment of these Figs. 1 and 2 I have shown alternatingly burnishing balls I and i" with sharpening balls 2 and 2". Any other arrangement is of course possible, such as two pairs of sharpening balls in the center with one pair of burnishing balls at either end, or three pairs of sharpening balls with one pair of burnishing balls at one end.

In the embodiment of Figs. 1 and 2 I showed socket plates 5 and 5 with coil springs 8 and 8. In the embodiment Figs. 4 and 5 I have shown socket plates 5 and 5 with flat springs l0 and I0. Either type spring can be used, of course, for either embodiment, although the coil spring ismore adapted for the small embodiment of Figs. 1 and 2 and the flat sprin is more adapted for the wider embodiment of Figs. 4 and 5.

Either embodiment may be used for any purpose desired. The embodiment of Figs. 4 and 5 is particularly designed, however, for large elongated blades, as used e. g. in the case of carving: knives, butcher knives, etc.

What I claim is:

A blade sharpening device, comprising a plurality of pairs of juxtaposed sharpening elements. in contact with each other and having at the point of contact a rounded surface, at least one pair having an abrasive surface, to constitute a grinding means, and at least one pair having a smooth surface, to constitute a burnishing means, the elements of each pair being held in firm frictional contact with each other and without rotative movement during the sharpening operation, said pairs acting simultaneously on the blade during the sharpening operation.

RONALD R. SPENCER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,353,485 McGall Sept. 21, 1920 1,469,147 Bird Sept. 25, 1923 FOREIGN PATENTS Number Country Date 113,251 Great Britain Feb. 14, 1918 191,380 Great Britain Oct. 4, 1923 

